WO2019037370A1

WO2019037370A1 - Hud illumination system, head-up display device and realization method

Info

Publication number: WO2019037370A1
Application number: PCT/CN2017/118987
Authority: WO
Inventors: 苗顺平; 马斌斌; 闵剑锋
Original assignee: 苏州车萝卜汽车电子科技有限公司
Priority date: 2017-08-22
Filing date: 2017-12-27
Publication date: 2019-02-28
Also published as: JP2020531925A; JP6921327B2; DE112017007958T5; CN107577046A; US20200225470A1; CN107577046B

Abstract

A head-up display (HUD) illumination system (1), a HUD device and a realization method. The system comprises a collimating uniform unit (111) and an intensity distribution adjusting unit (112); the collimating uniform unit is used for converting an incident light source into collimating uniform light beams; the intensity distribution adjusting unit is used for realizing illumination in which different points have different intensity distributions; the collimating light beams of the collimating uniform unit have uniform illumination on cross sections of the light beams; and output light beams of the intensity distribution adjusting unit are matched with an optical imaging system (3) of the HUD. The HUD illumination system is matched with the HUD optical imaging system, so that the illumination light beams are concentrated on an eye box area, and illumination efficiency is improved; compared with a single-lens illumination system, elements of the illumination system are thinner; moreover, the illumination area of the HUD illumination system is not limited to being circular, but also can be rectangular, square, and the like.

Description

HUD illumination system, head up display device and implementation method

This application claims priority to Chinese Patent Application No. 201710725237X, entitled "HUD Lighting System, Head-Up Display Device, and Implementation Method", filed on August 22, 2017, the entire contents of which are hereby incorporated by reference. Combined in this application.

Technical field

The invention relates to the field of optical field, LED illumination field and vehicle head-up display device (HUD), in particular to a HUD illumination system and an implementation method thereof, which can be applied to an automobile HUD vehicle head-up display device.

Background technique

In order to facilitate the driver to watch vehicle information, navigation information, etc. during driving, the head-up display device HUD is often used to optically project image information near the driver's line of sight to avoid looking down at the dashboard. Looking up the image projected in the display device, the entire image can be seen in the vicinity of the driver's eyes (hereinafter referred to as the eye box area), and the brightness of the image is uniform.

The HUD composition common in the prior art is as shown in FIG. 1, and mainly includes: an illumination system 1, an illumination LCD 2, an imaging optical system 3, an eye box area 4, and a projection virtual image 5. The core issues of lighting systems in HUD are: uniformity, efficiency and volume, specifically

1) Efficiency means that after the illumination beam is reflected by the imaging optical system 3, it enters the eye box area 4 as much as possible to achieve high-efficiency illumination;

2) Uniformity means that the virtual image 5 viewed in the eye box area 4 needs to satisfy the brightness of each point of the picture;

3) Volume means that the head-up display device has a compact volume structure.

In order to solve the above problems, two methods are mainly used at present, one is a reflective method, as shown in FIG. 2, including: LED, reflective surface and illumination surface, and the structure is compact. The main problem is that the illumination divergence angle is large, the light intensity distribution at each point on the illumination surface is basically the same, and the light intensity distribution is not matched in the HUD imaging optical system, so that the illumination efficiency is lowered, which affects the brightness of the HUD image. The other is a lens group method in which the LED beam distribution is first collimated into non-uniform near-parallel light, and a Kohler illumination path is used to adjust the uniformity of the illumination surface. The problem of uniformity of illumination surface and illumination efficiency is solved, but the structure is often large. In order to achieve the above objectives, the illumination system needs to satisfy: 1) the intensity distribution on the illuminated surface LCD matches the HUD imaging optical system. 2) The illumination space is evenly distributed on the illuminated surface LCD.

In addition, HUD needs to achieve low power consumption, high brightness, small size, and compact structure. An important part of it is backlighting system, how to provide a lighting system that can reduce system power consumption and ensure compact structure. It is used in a head-up display device. Application content

The technical problem to be solved by the present invention is to provide a HUD illumination system that realizes low power consumption, high brightness, small volume, and compact structure of the head-up display device.

The head-up display device of the present invention comprises at least a liquid crystal display panel (LCD), an imaging optical system, and a lighting system. The imaging optical system projects an image displayed on the LCD to form a virtual image in front of the driver. The LCD itself does not illuminate, it illuminates the LCD by the illumination system.

To solve the above technical problem, the present invention provides a HUD illumination system including: a collimation uniform unit and an intensity distribution adjustment unit,

In the collimating uniform unit for converting the incident light source into a collimated uniform beam,

In the intensity distribution adjusting unit, the illumination for different light intensity distribution according to different points,

The collimated beam in the collimating uniform unit has uniform illumination over the beam cross section, and the output beam in the intensity distribution adjusting unit matches the imaging optical system in the HUD.

Further, the collimating uniform unit directly shapes the light beam emitted from the light source into a cross section set according to requirements by refraction or reflection of light.

Further, the collimating uniform unit includes at least two optical elements, and the optical element includes: a first optical element and a second optical element,

The first optical element and the second optical element have a front surface that is a free curved surface and a rear surface that is a flat surface.

Alternatively, the first optical element and the second optical element have a front surface that is a flat surface and a rear surface that is a free curved surface.

Alternatively, at least two of the first optical element and the second optical element are free-form surfaces.

Further, the intensity distribution adjusting unit comprises: an optical element for refracting or reflecting, and the light intensity distribution is matched by the HUD imaging optical system.

Still further, the system further includes: a diffusing element for scattering the incident beam, the diffusing element being any one of a diffusion film or a microlens array.

Further, if the illumination area needs to be increased, the HUD illumination system is arranged in an array.

Further, in the collimating uniform unit, when the illumination surface is circular, the free curved surface may be a rotationally symmetric aspheric surface, and/or, when the illumination surface is a non-circular surface, the free surface is non-rotationally symmetric. Surface.

Further, in the collimating uniform unit, the cross section may be a circle, a square, or a rectangle.

Further, the light exit surface of the uniform collimated optical path is a plane, and the light incident surface of the intensity distribution adjusting element is a plane. At this time, the planes of the two elements can be combined to reduce the number of components of the entire illumination system.

Further, in the intensity distribution adjusting unit, the light incident surface is a plane, the exit surface is a spherical surface or a curved surface, and the shape of the eye box is adjusted by adjusting the angular intensity distribution forms of the respective positions.

Further, in the collimating uniform unit, the incident light source beam is converted into a collimated light beam by means of refraction, reflection and/or diffraction of light, and the illuminance is uniform on the beam cross section.

Based on the above, the present invention also provides a head-up display device comprising: an illumination system, an illumination LCD, an imaging optical system, an eye box region 4, and a projected virtual image, wherein the light source beam emitted by the illumination system sequentially passes through the illumination LCD and the imaging optical system. In the eye box area, the illumination system is the HUD illumination system described.

Based on the above, the present invention also provides a method for implementing a HUD illumination system, comprising the following steps:

S1 sends the light beam emitted by the light source to the eye box area through the collimation uniform unit, the intensity distribution adjusting unit, the LCD, and the imaging optical system.

S2 is in the collimating uniform unit for converting the incident light source into a collimated uniform beam.

S3 is used in the intensity distribution adjusting unit to illuminate different light intensity distributions according to different points.

The collimated beam in the collimating uniform unit of S4 is uniform in illuminance on the beam section, and the output beam in the intensity distribution adjusting unit is matched with the imaging optical system.

The beneficial effects of the invention:

1) In the HUD illumination system of the present invention, since the method includes: a collimation uniform unit and an intensity distribution adjustment unit, the collimation uniform unit is used to convert the incident light source into a collimated beam, and the collimation is uniform The collimated beam in the cell has uniform illumination over the beam cross section. The intensity distribution adjusting unit is configured to perform illumination of different light intensities according to different point distributions, and the output beam in the intensity distribution adjusting unit is matched with the imaging optical system in the HUD. Thus, the HUD illumination system of the present application can be matched with the HUD optical imaging system, so that the illumination beam is concentrated in the eyebox area, improving illumination efficiency. Compared with the single-lens uniform collimated illumination system, the method of the present invention improves the exit angle of light on the lens, which is advantageous for improving efficiency.

2) In addition, since the collimation uniform unit and the intensity distribution adjusting unit can reduce the number of components, the overall volume of the illumination system is compact. A uniformly collimated illumination system utilizes a thinner component thickness than a single lens uniform collimated illumination system.

3) In the HUD illumination system of the present invention, the illumination area is not limited to a circular shape, and may be a rectangle, a square, or the like.

DRAWINGS

1 is a schematic diagram of the composition of a HUD in the prior art;

2 is a schematic view of a reflective method in the prior art;

3 is a schematic structural diagram of a HUD illumination system according to an embodiment of the present invention;

Figure 4 is a schematic view of the combined structure of Figure 3;

FIG. 5 is a schematic structural view of an illumination system according to an embodiment of the present invention; FIG.

6 is a schematic diagram of an optical path of a collimating uniform unit in an embodiment of the present invention;

7 is a schematic diagram of an optical path of an intensity distribution adjusting unit according to an embodiment of the present invention;

Figure 8 is a schematic view showing the structure of the microlens;

Figure 9 is a schematic view of the front view angle of Figure 8;

10(a) and 10(b) are schematic views showing the structure of the array in the xy-axis direction and the xz-axis direction;

11 is a flow chart showing the implementation method of the HUD illumination system of the present invention.

Detailed ways

The technical solutions in the embodiments of the present application are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present application. Some embodiments are applied, not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without departing from the inventive scope are the scope of the present application.

In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "medium", The orientation or positional relationship of the indications "vertical", "horizontal", "transverse", "longitudinal", etc. is based on the orientation or positional relationship shown in the drawings. These terms are primarily intended to describe the present application and its embodiments, and are not intended

Moreover, the above partial terms may be used to indicate other meanings in addition to the orientation or positional relationship, for example, the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meaning of these terms in this application can be understood on a case-by-case basis.

In addition, the terms "installation," "set," "set," "connected," "connected," and "socketed" are to be understood broadly. For example, it may be a fixed connection, a detachable connection, or an integral construction; it may be a mechanical connection, or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, or it may be two devices, components or components. Internal communication. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood on a case-by-case basis.

Unless otherwise stated, "multiple" means two or more.

The present application will be further described in detail below through specific embodiments and with reference to the accompanying drawings.

3 is a schematic structural diagram of a HUD illumination system according to an embodiment of the present invention. A HUD illumination system in this embodiment includes: a collimation uniformity unit 111 and an intensity distribution adjustment unit 112, where the alignment is uniform The unit 111 is configured to convert the incident light source into a collimated light beam, and the intensity distribution adjusting unit 112 is configured to illuminate different light intensity distributions according to different points, and the collimated light beam in the collimating uniform unit 111 is The illuminance on the beam section is uniform, and the output beam in the intensity distribution adjusting unit 112 matches the imaging optical system in the HUD. The light source used in the HUD illumination system in this embodiment may be an LED light emitting diode or an LD semiconductor laser. The LD source emits a beam of approximately collimated beam, achieving a uniform alignment process that is different from the LED source. For different light sources, the idea of achieving illumination is consistent. In the collimation uniform unit 111, the uniform collimation method of the light source is not limited, and a uniform collimated optical path may be combined for refraction or refraction reflection. In the intensity distribution adjusting unit 112, the intensity distribution of the uniform collimated light is adjusted by spherical refraction or reflection, and is implemented with a light diffusing element, so that the beam cross section and the eye box area are basically after the illumination beam passes through the HUD imaging optical system. Consistent, or may be slightly larger than the eye box area.

In some embodiments, a uniform collimating optical path is also provided in the HUD illumination system of the embodiment, which is composed of at least two components, and the optical beam is directly refracted by the optical element to refract light. A cross section is required, including but not limited to, a circle, a square, a rectangle, and the like. From the direction of light source transmission, the first element and the second element are in turn. The first component is adjacent to the LED and the second component is remote from the LED. Specifically, the first element is planar near the surface of the LED, and the other surface is a free curved surface. The surface of the second component near the LED is a free-form surface, and the other surface is a flat surface.

In some embodiments, the first element and the second element have a total of four surfaces, and more than one surface is a freeform surface.

In some embodiments, when the illumination surface is circular, the freeform surface may be a rotationally symmetric aspheric surface.

In some embodiments, when the illumination surface is a non-circular surface such as a square or a rectangle, the free surface is a non-rotationally symmetric surface.

Preferably, the light source intensity distribution of the LED source is a Lambertian type or any other known form of light intensity distribution.

In some embodiments, the intensity distribution adjustment unit 112 in this embodiment can be implemented by more than one optical element, which can be a refractive or reflective element. The output beam is matched to the HUD imaging optics, ie the intensity distribution of the illumination to different points on the LCD is different.

Preferably, a diffusion sheet may be added between the LCD and the optical element to further adjust the intensity distribution to make the illumination surface evenly soft.

Preferably, the intensity distribution adjusting unit 112 is an intensity distribution adjusting element, wherein the light incident surface is a plane, and the exit surface is a spherical surface or a curved surface.

Preferably, the intensity distribution adjusting unit of the intensity distribution adjusting unit 112 adjusts the shape of the eye box by adjusting the form of the intensity distribution of the respective positions, such as adjusting the shape of the eye box to be a rectangle, a square, an ellipse or the like.

Preferably, when the light exit surface of the uniformly collimated optical path in the collimation uniform unit 111 is a plane, the light incident surface of the intensity distribution adjusting element is a plane, and at this time, the planes of the two elements may be combined for reducing the entire illumination system component. Quantity.

Since the collimation uniformity unit 111 and the intensity distribution adjustment unit 112 can reduce the number of components, the overall volume of the illumination system is compact. A uniformly collimated illumination system utilizes a thinner component thickness than a single lens uniform collimated illumination system.

Preferably, the HUD illumination system in this embodiment may be arranged in an array and spliced to increase the illumination area. Including but not limited to: 1×2 array, 2×2 array, etc., the arrangement may be rectangular, hexagonal, or the like.

4 is a schematic diagram of the combined structure of FIG. 3. The light beam emitted by the light source 113 passes through the uniform collimating unit 111, the intensity distribution adjusting unit 112, the LCD 2, and the HUD imaging optical system 3 to the eye box region (not shown). Since the incident light source beam is converted into a collimated light beam by means of refraction, reflection or diffraction of light in the uniform collimation unit 111, it is satisfied that the illuminance is uniform on the beam cross section. The intensity distribution adjusting unit 112 is realized by one or more optical elements, and may be a refractive or reflective element. And the satisfaction: the output beam is matched with the HUD imaging optical system, that is, the intensity distribution of illumination to different points on the LCD is different. Since the angle of the light at each point on the LCD is different from the angle of the LCD, it is more advantageous for matching the imaging optical system of the HUD and for the application in the head-up display device.

As a preferred embodiment of the present invention, reference is made to FIG. 5, which is a schematic structural diagram of an illumination system according to an embodiment of the present invention. The illumination system 1 (including at least the light source 113, the collimation uniform unit 111, and the intensity distribution adjustment unit 112) outputs beam illumination. To LCD 2. Taking the center point and the upper and lower edges of the LCD as an example, according to the requirements of the HUD imaging optical system, the light intensity distribution of the center point on the LCD is indicated by the light rays 610, 611, and 612 in the cross section. 610 is the main ray, and 611 and 612 are the edge rays respectively. At this point, the light is concentrated in the angle formed by the

rays

611 and 612, and the light intensity distribution is substantially uniform within this angle. Similarly, the two points of light on the edge are 620-621 and 630-631. At different points on the LCD, the angles of the

chief ray

610, 620, 630 and the LCD are A1, A2, and A3, respectively, and generally A1 ≠ A2, A3 ≠ A2.

6 is a schematic diagram of an optical path of a collimating uniform unit in an embodiment of the present invention. The uniform collimated light in the collimating uniform unit 111 in this embodiment is composed of at least two components, and the optical component is used for light. Refraction, directly shaping the beam from the source into the required cross section, including but not limited to, circular, square, rectangular, and the like. As shown in FIG. 6, from the direction of light source transmission, the light emitted by the light source 11 is sequentially irradiated to the LCD 2 through the element 12 and the element 13, and the light is as shown in steps 110 to 114, which are parallel to each other, and the illumination spot is substantially square in cross section, and is evenly distributed on the LCD. distributed. The materials of the

components

12 and 13 are optical plastics, and through injection molding, even if the curved surface is complicated, rapid mass production can be realized. The front and rear surfaces of the element 12 are 121 and 122, respectively. In this example, the front surface is a flat surface, and the rear surface is a free curved surface. The front and rear surfaces of the element 13 are respectively 131 and 132. In this example, the front surface is a free curved surface, the rear surface is a flat surface, and the front surface can be adjusted to a flat surface, and the rear surface is adjusted to a free curved surface. Two components, four surfaces, at least 2 surfaces are free-form surfaces. Preferably, when the cross-sectional shape of the illumination spot is circular, the free curved surface in the

elements

12, 13 is changed to a rotationally symmetric aspherical surface. In the HUD illumination system of this embodiment, the illumination area is not limited to a circular shape, and may be a rectangle, a square, or the like.

In some embodiments, the uniform collimation can also be achieved by using a double aspheric lens in the collimation uniformity unit 111, resulting in a circular cross section of the beam. For details, please refer to Chinese patent CN103148443 A. However, when the illumination area is large, the corresponding edge light on the beam cross section has a large angle of refraction at the exit surface of the lens, which affects engineering applications. As the illumination area increases, the lens thickness needs to increase accordingly. Therefore, it is not a preferred embodiment in the present application.

Please refer to FIG. 7 , which is a schematic diagram of an optical path of an intensity distribution adjusting unit according to an embodiment of the present invention. The intensity distribution adjusting unit 112 is configured by one or more optical elements and may be a refractive or reflective element. The output beam is matched to the HUD imaging optics, ie the intensity distribution of the illumination to different points on the LCD is different. As shown in Fig. 7, the intensity distribution adjusting unit 112 is composed of an element 14 and a member 15, wherein the element 14 is a refractive element, the light incident surface is a flat surface, and the exit surface is a curved surface. Element 15 is a diffusing element that scatters the incident beam. Reasonably select the parameters of the

components

14, 15 and evenly collimate the beam, and illuminate it onto the LCD 2. The light distribution in the cross section is shown in Fig. 7, respectively, 710-712, 720-722, 730-732, light intensity distribution and HUD. Imaging optical system matching.

As a preferred embodiment in the present embodiment, FIG. 8 is a schematic view of a microlens array structure, and the diffusion element 15 described above may be selected as a diffusion film or a microlens array. Figure 8 is a schematic view of a microlens array. The front surface 161 of the element 16 is planar, the rear surface 162 is curved, and the curved surface is covered with a microlens array. Front View Referring to FIG. 9 is a schematic view of the front view angle in FIG. 8. The shaded area is one of the microlenses, the length L of the microlens, and the width W. The aspect ratio L/W is generally consistent with the aspect ratio of the eye box area.

Please refer to FIG. 10(a) and FIG. 10(b) are schematic diagrams of the x, y-axis direction, x, and z-axis directions of the array arrangement, and the array arrangement. The HUD illumination system in this embodiment can be arranged according to the array. Cloth, and splicing to increase the lighting area. As shown in Fig. 10 (a) and Fig. 10 (b), the array is arranged in a 2 × 3 array. Under the same conditions, the increased illumination area and the increase in the number of LEDs utilize the increase in overall luminous flux. It should be noted that for array arrangement, light can cause crosstalk, and a group of uniformly collimated HUD illumination systems can crosstalk into another adjacent group. It can be occluded by adding structural members, and since the angle of light entering the adjacent group in consideration of crosstalk is generally 20 to 40°, it does not enter the eyelid region after passing through the subsequent components. Therefore, the impact on the final human eye viewing imaging is limited, which can be ignored in this embodiment.

Also disclosed in the embodiment is a head-up display device, which mainly comprises: an illumination system, an illumination LCD, an imaging optical system, an eye box region 4 and a projection virtual image, and the light source beam emitted by the illumination system sequentially passes through the illumination LCD and the imaging optical system. To the eye box area, preferably, the illumination system is the HUD illumination system described above.

The collimating uniform unit in the above HUD illumination system includes at least two optical elements, and the light beam emitted by the light source is directly shaped into a cross section set according to requirements by refraction of light.

Preferably, the two optical elements in the HUD illumination system include: a first optical element and a second optical element, the first optical element and the second optical element, the front surface is a free curved surface, and the rear The surface is planar, or the first optical element and the second optical element have a front surface that is planar and a rear surface that is a free curved surface, or at least two of the first optical element and the second optical element are free Surface.

The intensity distribution adjusting unit in the HUD illumination system described above includes: an optical element for refracting or reflecting, and the light intensity is distributed in the HUD imaging optical system to match.

The HUD illumination system further includes a diffusing element for scattering the incident light beam, the diffusing element being either a diffusion film or a microlens array.

In some embodiments, the HUD illumination system described above arranges the HUD illumination systems in an array if it is desired to increase the illumination area.

In some embodiments, in the above HUD illumination system, in the collimation uniform unit, when the illumination surface is circular, the free curved surface may be a rotationally symmetric aspheric surface, and/or when the illumination surface is a non-circular surface When the free surface is a non-rotationally symmetric surface.

In some embodiments, in the above HUD illumination system, in the collimating uniform unit, the cross section may be circular, square, or rectangular.

In some embodiments, in the HUD illumination system described above, the light exit surface of the uniform collimated optical path is a plane, and the light incident surface of the intensity distribution adjusting element is a plane. At this time, the planes of the two components may be combined to reduce the entire illumination. The number of system components.

In some embodiments, in the HUD illumination system described above, the light incident surface of the intensity distribution adjusting unit is a plane, the exit surface is a spherical surface or a curved surface, and the shape of the eye box is adjusted by adjusting the angular intensity distribution of each of the positions.

In some embodiments, the HUD illumination system described above converts an incident light source beam into a collimated beam by means of refraction, reflection, and/or diffraction of light in the collimation uniform unit, and on the beam cross section. Uniform illumination.

Please refer to FIG. 11 , which is a schematic flowchart of a method for implementing a HUD illumination system according to the present invention. The method includes the following steps:

Step S1 sends the light beam emitted by the light source to the eyelid region through the collimation uniform unit, the intensity distribution adjusting unit, the LCD, and the imaging optical system.

Step S2 is in the collimating uniform unit for converting the incident light source into a collimated light beam. Preferably, the collimating uniform unit in the step S2 includes at least two optical elements, and the light source is refracted by the light. The emitted beam is directly shaped into a cross section set according to requirements. The two optical elements include: a first optical element and a second optical element, the first optical element and the second optical element, the front surface is a free curved surface, the rear surface is a plane, or the first The optical element and the second optical element have a front surface that is planar and a rear surface that is a free curved surface, or at least two of the first optical element and the second optical element are free-form surfaces.

In step S3, the intensity distribution adjusting unit is configured to illuminate different light intensity distributions according to different points. In the step S3, the intensity distribution adjusting unit includes: an optical component for refracting or reflecting, light intensity Distributed in the HUD imaging optical system, further comprising: a diffusing element for scattering the incident beam, the diffusing element being either a diffusion film or a microlens array.

The collimated beam in the collimating uniform unit in step S4 has uniform illumination on the beam cross section, and the output beam in the intensity distribution adjusting unit is matched with the imaging optical system.

In the above steps, if it is necessary to increase the illumination area, the HUD illumination system is arranged in an array.

In the above steps, when the illumination surface is circular, the free surface may be a rotationally symmetric aspheric surface, and/or, when the illumination surface is a non-circular surface, the free surface is a non-rotationally symmetric surface.

In the above steps, the cross section may be a circle, a square, or a rectangle.

In the above steps, the light exit surface of the uniform collimated optical path is a plane, and the light incident surface of the intensity distribution adjusting element is a plane. At this time, the planes of the two elements can be combined to reduce the number of components of the entire illumination system.

In the above step, the light incident surface of the intensity distribution adjusting unit is a plane, the emitting surface is a spherical surface or a curved surface, and the shape of the eye box is adjusted by adjusting the intensity distribution pattern of the respective angular positions.

In the above steps, in the collimating uniform unit, the incident light source beam is converted into a collimated light beam by means of refraction, reflection and/or diffraction of light, and the illuminance is uniform on the beam cross section.

The above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and various changes and modifications may be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application are intended to be included within the scope of the present application.

Claims

A HUD illumination system, comprising: a collimation uniform unit and an intensity distribution adjustment unit,

In the collimating uniform unit for converting the incident light source into a collimated uniform beam,

In the intensity distribution adjusting unit, the illumination for different light intensity distribution according to different points,

The collimated beam in the collimating uniform unit has uniform illumination over the beam cross section, and the output beam in the intensity distribution adjusting unit matches the imaging optical system in the HUD.
The HUD illumination system according to claim 1, wherein said collimation uniform unit directly shapes a light beam emitted from the light source into a cross section set according to requirements by refraction or reflection of light.
The direct HUD illumination system according to claim 2, wherein said collimating uniform unit comprises at least two optical elements, and wherein said two optical elements comprise: a first optical element and a second optical element,

The first optical element and the second optical element have a front surface that is a free curved surface and a rear surface that is a flat surface.

Alternatively, the first optical element and the second optical element have a front surface that is a flat surface and a rear surface that is a free curved surface.

Alternatively, at least two of the first optical element and the second optical element are free-form surfaces.
The HUD illumination system according to claim 1, wherein said intensity distribution adjusting unit comprises: an optical element for refracting or reflecting, the light intensity distribution being matched with the HUD imaging optical system.
The HUD illumination system of claim 4, further comprising: a diffusing element for scattering the incident beam, the diffusing element being any one of a diffusion film or a microlens array.
A HUD illumination system according to any one of claims 1-5, wherein the HUD illumination system is arranged in an array if it is desired to increase the illumination area.
The HUD illumination system according to any one of claims 1 to 5, wherein, in the collimating uniform unit, when the illumination surface is circular, the free curved surface may be a rotationally symmetric aspheric surface, and/or when When the illumination surface is a non-circular surface, the free surface is a non-rotationally symmetric surface.
The HUD illumination system according to any one of claims 1 to 5, wherein in the collimating uniform unit, the cross section may be a circle, a square, or a rectangle.
The HUD illumination system according to any one of claims 1 to 5, characterized in that the light exit surface of the uniform collimated optical path is a plane, and the light incident surface of the intensity distribution adjusting element is a plane. At this time, the plane of the two components can be Merger to reduce the number of components in the entire lighting system.
The HUD illumination system according to any one of claims 1 to 5, characterized in that, in the intensity distribution adjusting unit, the light incident surface is a plane, the exit surface is a spherical surface or a curved surface, and the adjustment is made by adjusting the intensity distribution forms of the respective angular positions. The shape of the eye box.
A HUD illumination system according to any one of claims 1 to 5, wherein in the collimating uniform unit, the incident light source beam is converted into collimation by means of refraction, reflection and/or diffraction of light. The beam, and the illumination is uniform across the beam section.
A head-up display device comprising: an illumination system, an illumination LCD, an imaging optical system, an eye box region 4, and a projection virtual image, wherein the light source beam emitted by the illumination system sequentially passes through the illumination LCD and the imaging optical system to the eye box region, wherein The illumination system is the HUD illumination system of any of claims 1-5.
A method for implementing a HUD illumination system, comprising the steps of:

S1 sends the light beam emitted by the light source to the eye box area through the collimation uniform unit, the intensity distribution adjusting unit, the LCD, and the imaging optical system.

S2 is in the collimating uniform unit for converting the incident light source into a collimated uniform beam.

S3 is used in the intensity distribution adjusting unit to illuminate different light intensity distributions according to different points.

The collimated beam in the collimating uniform unit of S4 is uniform in illuminance on the beam section, and the output beam in the intensity distribution adjusting unit is matched with the imaging optical system.